ADAU1452 - Upsampling cuases wrong smpalerate at Delay
Hi,
I'm using ADAU1452 in a project with 48kHz.
Because I need shorter delays than 20µs (=1 Sample @ 48kHz) I change the sampling rate via up samling V1.02 e.g. to 96kHz. For further editing I change the Sample Rate for new items to 96kHz. The outputs are are also set to 96kHz, I2S with 96kHz looks pretty fine on my scope.The now placed delay block (VCD v2.00) with value <one sample> should delay for 10µs, right? But it does not.
In the Link window the frequency for the delay block is shown right with 96kHz but each sample causes a delay of 20µs. So the delay block works with 48kHz.
Any ideas what I can do to configure the delay correctly?
Many thanks,
Didi
Audio Signal Processors
adau1452
software
4.7
upsampling
SigmaDSP Audio Processors
VCD
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Hello Didi,
It seems like you only set the software fs to 96KHZ. I'm not sure whether you set the core rate to be 96KHZ. Have you set your Clock Generator's N/M ratio to 1/3 to get 96KHZ?. As you mentioned that outputs and I2S set to 96KHZ. I assume that you only set the serial port FS rate into FS*2 ? But that won't be giving you a correct result.
To stop adding the assumptions. Can you please send your project? It will be easy for us to quickly look through and debug it.
Regards,
Harish
Didi,
Do you really need to run at a higher sample rate? If all you want is better delay resolution, I suggest that you look at the fractional delay block. This interpolates between samples giving sub-sample delay resolution.
Best regards,
Ken
Harish, many thanks!
Start pulse had the wrong freqiuency selection.
Hi Ken, since all existing and used blocks are based on VCD I try to integrate new projects. But I'll check the idea with fractional delay. Many thanks for this suggestion! Didi
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